Resetting a Lost Admin Password

The normal ways to recover a lost password are:

Click the password reset link on the login screen; this appears
after a failed login attempt. This works only if you have entered your
email address on your Personal page in the ownCloud Web interface, so
that the ownCloud server can email a reset link to you.

Ask another ownCloud server admin to reset it for you.

If neither of these is an option, then you have a third option, and that
is using the occ command. occ is in the owncloud directory, for
example /var/www/owncloud/occ. occ has a command for resetting all
user passwords, user:resetpassword. It is best to run occ as the
HTTP user, as in this example on Ubuntu Linux: